OCD is a significant mental health concern. The identification of potential risk factors that may contribute to the development, maintenance and exacerbation of OCD in children remains understudied. OCD affects one to three percent of children and adolescents. Recent research suggests that family contextual factors may be a particularly promising domain for understanding and treating OCD and related disorders. The goal of the proposed research is to gain an understanding of family environmental factors and parent-child interactions involved in childhood OCD. More specifically, the proposed research will explore specific familial environmental factors and interaction patterns that occur in families of children with OCD, non-OCD anxiety disorders and no diagnosis. In addition, within the OCD group, the specificity of observed interaction will be examined by comparison to parent-unaffected sibling interaction. Ninety parent-child dyads (plus 20 siblings) will be assessed via self-report and behavioral observation methodology. The current study will enhance our knowledge of family contextual factors in childhood OCD and other anxiety disorders and aid in the development of prescriptive treatment and prevention approaches for these disorders.